DIY laser

Anyone with a record player is familiar with the concept of translating irregularities on a surface into sound. And, anyone who has ever cracked open a CD player or DVD player has seen how a laser can be used to reproduce sound digitally. Combining the two would be an interesting project in its own right, but [Dimitry Morozov] took this a couple of steps further with his pyrite disc sound object project.

Pyrite discs, also known as pyrite suns or pyrite dollars, are a form of pyrite in which the crystallization structure forms a disc with radial striations. Pyrite discs are unique to the area around Sparta, Illinois, and are generally found in coal mines there. They have no real practical use, but are a favorite of mineral collectors because of their interesting aesthetics.

[Dmitry] received his pyrite disc from one such mineral collector in Boulder, CO, with the request that he use it for an interesting project. [Dmitry] himself specializes in art installations and unique instruments, and combined those passions in his pyrite disc sound object called Ra.

The concept itself is straightforward: spin the pyrite disc and use a laser to convert the surface striations into audio. But, as you can see in the photos and video, the execution was far from straightforward. From what we can gather, [Dimitry] used an Arduino Nano and a DIY laser pickup on a servo arm to scan the pyrite disc as it’s being spun by a stepper motor. That data is then sent to a Raspberry Pi where it’s synthesized (with various modulation and effects controls), to produce sound that is output through the single speaker attached to the object. Generating sound from unusual sources is certainly nothing new to regular readers, but the beauty of this part project is definitely something to be applauded.

Despite being able to cut wood, paper, and a bunch of other everyday materials, a carbon dioxide laser is actually surprisingly simple. All you need to do is fill a tube with CO2, put some mirrors and lenses on each end, and run an electric current through the gas. In practice, though, there’s a lot of extra bits and bobs required for a working laser.

[ThunderSqueak] will need some sort of cooling for his laser, and for that he’s constructed a watercooling jacket out of 2″ PVC. In the end caps, a pair of brass pipe fittings are JB Welded in place, allowing a place for the mirror assembly and lenses.

The mirror mounts are the key component of this build, but the construction method is surprisingly simple. [ThunderSqueak] is using a few brass barbed hose fittings, with washers stuck on one end. The washers are drilled to accept a trio of bolts that will allow the mirrors to be perfectly parallel; anything less and the CO2 won’t lase.

The build isn’t complete yet, but having already built a few lasers, there’s little doubt [ThunderSqueak] will be able to pull this one off as well.

Being able to create PCB’s at home is a milestone in the DIYer’s arsenal. Whether you physically mill or chemically etch boards, it’s a tricky task to perfect. [Charlie & Victor] are working towards a solution to this complicated chore. They call their machine the DiyouPCB. DiyouPCB is an open source PCB etching project consisting of both hardware and software components.

The project is based on using a Blue Ray optical pickup. The pickup was used in its entirety, without any modification, to simplify the build process. In order to use the stock pickup, [Charlie & Victor] had to reverse engineer the communication protocol which also allowed them to take advantage of the auto-focus feature used while reading Blue Ray discs. The frame of the machine is reminiscent of a RepRap, which they used to do preliminary testing and laser tuning. The X and Y axes run on brass bushings and are belt driven by stepper motors which are controlled by an Arduino through a specially designed DiyouPCB Controller Shield.

[LokisMischief] wrote in to the tip line to let us know about this incredible home made CO2 laser. This thing is a complete DIY beauty, from the PVC cooling jacket to the toolbox based controller. The whole thing is essentially built from DIY parts, hand blown glass for the laser tube, plumbing store mirror mounts, a PVC cooling jacket with a caulked glass viewing window, and a neon sign transformer with a variac to control output. Even the optics are completely DIY, a hand drilled gold mirror and a NaCL window made from a polished chunk of icecream salt! [ThunderSqueak] says the control box only cost 60 bucks, and the rest of the parts don’t look too terribly expensive.

We could only find one video of the setup in the variac section of the site, and it was just a test the amp meter in the controller (no lasing anything at all). [ThunderSqueak] does make a note on the to do list about doing a good laser-y demonstration video, which we are looking forward to.